1. Field of the Invention
The present invention relates to degreaser/cleaning compositions. More particularly, the invention relates to degreaser/cleaning compositions useful for removing cooking oil or shortening and buildups thereof from metallic surfaces.
2. Brief Discussion of the Related Art
The deposits of cooking oils, shortenings, polymerized products and carbonized products occurs on kitchen surfaces such as kitchen stove ventilation hoods, kitchen exhaust stacks, and kitchen exhaust fans in restaurants and commercial institutions. As mandated by the National Fire Code, commercial kitchens are required to regularly clean and remove grease from kitchen exhaust systems to prevent excessive buildup and potential grease fires. In the related art, degreaser/cleaning solutions are difficult to use in removing grease as compared with the degreaser/cleaning composition provided in the present invention.
Deep-fat fryer oil emissions to kitchen exhaust systems generally comprise polymerized and carbonized soils of fats and oils which are typically removed with hazardous, highly alkaline, caustic soda or silicate based corrosive cleaners. This poses potential hazards to users of degreaser/cleaning chemicals due to overspray and overuse of caustic chemicals. Alternatively, degreaser/cleaning applications in the related art call for milder but less effective compositions.
Also, cleaning solutions in the related art will emulsify grease, oil and the like, which will eventually wash out to a sewer-drain. Therefore, the industry requires a biodegradable and environmentally friendly degreaser to cause little or minimal negative ecological impact.
Typically, phosphates are used in degreaser/cleaning compositions. The incorporation of alkali phosphates provide for more effective rinsing of the degreaser/cleaning solution from treated surfaces. Alkali phosphates also sequester metal ions, act as buffers and synergists for the surfactants. Past attempts to control phosphate effluents for environmental reasons have reduced their concentration to fairly low limits. However, in the related art, meeting these constraints by lowering phosphate concentrations has met with some difficulty in that low phosphate cleaners do not perform effectively in meeting their designed objectives. Furthermore, phosphate-free detergent and degreaser compositions in the related art do not give entirely satisfactory results for clean up of cooking oils and fats or their polymerized and carbonized by-products that collect in commercial kitchen exhausts.
Applications of degreaser/cleaning solutions in the related art require multiple applications and a significant amount of time to breakdown grease and deposits. In the related art, it is difficult to determine whether degreaser/cleaning solutions adequately coat grease buildups, which leads to overspray, wastes degreaser/cleaning solutions, and prolongs exposure of users to degreaser/cleaning chemicals. More particularly, soiled surfaces not adequately treated with such degreaser/cleaning solutions are difficult to differentiate from soiled surfaces treated with such degreaser/cleaning solutions.
Therefore, degreaser/cleaning compositions in the related art are either ineffective for use in heavy duty cleaning operations, or too strongly corrosive for metallic surfaces and pose safety problems to users. Furthermore degreaser/cleaning compositions in the related art often contain toxic components, do not biodegrade and are environmentally unfriendly or otherwise unsuitable for large scale industrial and institutional use. Additionally, it is difficult to visually determine whether degreaser/cleaning compositions in the related art adequately coat grease stains in kitchen exhaust systems.
In summary, the use of cooking oils or shortenings worldwide has brought about a need to develop degreaser/cleaning compositions capable of effectively and efficiently cleaning and degreasing multiple kitchen surfaces with visual confirmation of application and removal.
Man, U.S. Pat. No. 6,506,261, discloses nonionic surfactants, silicone surfactants, anionic surfactants, hydrotropes and other optional functional materials including sequestrants. These organic compositions may be effective in removing complex organic soils from wood, metal and other hard surfaces, but do not visually enhance effective cleaning of tenacious polymerized/carbonized soil emitted from deep-fat fryers onto metallic surfaces such as kitchen exhausts.
MacNamara et al. U.S. Pat. No. 4,093,566 discloses a silicate based cleaning composition intended for cleaning metallic ammunition components. These highly alkaline compositions may be useful as a spray cleaner for removing oils and greases, but do not visually enhance effective cleaning of polymerized/carbonized soil from metallic surfaces.
Leiter et al., U.S. Pat. No. 4,844,744 discloses a phosphate-free single phase degreasing composition for cleaning aluminum surfaces. Leiter et al., however, is ineffective in removing polymerized and carbonized soils emitted from cooking and/or frying onto metallic surfaces.